Everards Brewery team leader Mick Trevor and Terrapin Beer Co. brewmaster Brian “Spike” Buckowski unlatched the lid of the Everards mash tun and peered through steamy haze at the thick, gooey grain bed containing 10% sticky rye malt. Draining the sweet wort from this glue-like porridge was proceeding slower than Trevor had anticipated. Seemingly unfazed, Buckowski assured everyone that this is what happens when a mash contains rye malt. Patience is important.

Located in the English town of Leicester, Everards cranks out a fine range of traditional British ales. Why was a brewer from Athens, GA, stressing out the Everards blokes last August by making a clone of Terrapin Rye Pale Ale on the Everards system? It was all part of an elaborate scheme by the United Kingdom’s immense chain of Wetherspoon pubs to bring over U.S. brewing celebrities to formulate cask clones of popular American beers at breweries around England.

Everards brewed seven batches of Terrapin’s award-winning Rye Pale Ale over three days, producing 1,750 cask firkins, with a couple of casks going to each of the 850 Wetherspoon pubs across England, Wales, Scotland and Northern Ireland. Cask ale (or “real ale”) is unfiltered beer containing no artificial carbon dioxide gas. A soft carbonation develops inside the cask from residual yeast and sugar, and, once tapped, the delicate ale must be consumed within a few days. This presented no problem with the Terrapin casks, as enthusiastic Wetherspoon patrons drained them all in a little over a week.

When asked why such an elaborate undertaking is worthwhile for Everards, Trevor explained, “Making a new recipe with a brewer from another country gives us valuable insight into techniques and ingredients for our specialty brews. It’s challenging at times—like with Spike’s rye malt—but worth it for the learning experience.”

Wetherspoon pubs pride themselves in stocking an impressive array of interesting cask ales from around the United Kingdom, and the chain also seems deeply interested in bringing a touch of popular American beer flare and creativity to its cask taps. There’s a bit of head-butting going on now in the United Kingdom between traditional cask ale enthusiasts and younger beer geeks, and Wetherspoon wants to bridge this gap with its international guest brewer program—illustrating that great cask ale and attention-grabbing beer can be “one and the same.”

“U.K. microbreweries seem to be heavily influenced by what U.S. brewers are doing these days, and often try to mimic their beer styles,” notes Everards head brewer Graham Giblett. “The Wetherspoon collaboration program could have a very significant influence on the type of cask beers produced in the U.K. in the future.”

Wetherspoon’s original idea in 2008 was to invite international brewers to create beers in the United Kingdom for the pub chain’s beer festivals held twice every year. “This was considered far more environmentally friendly than shipping thousands of gallons of beer across the world,” noted Wetherspoon spokesman Eddie Gershon. “It also served as a good way of enabling international brewers to showcase their beers in the United Kingdom, whilst still supporting the British brewing industry.”

Wetherspoon pub managers loved the buzz that the collaborations generated with customers. By 2013, the enormous popularity of the collaborative ales justified extending the program beyond the festivals and making the distinctive casks on a regular basis. “Consequently, the Wetherspoon American Craft Brewers’ Showcase was developed, and from September of 2013 we’ve had an American brewer visit the U.K. every two weeks to brew for us,” Gershon added.